THE SKELETON AND TEETH
more. Not only is the capacity greater, but the sexual differences are more pronounced.
In the Gibbon the capacity is 76 to 90 c.c., and the female skull lodges a brain"which is 98 per cent, of that of the male. In the Orang, on the other hand, according
FIG. 22.—Skull of the Orang-Outan.
to Hrdlicka, the capacity is 350 to 540 c.c. in the adult male, and 300 to 490 c.c. in the adult female (i.e., the capacity in the female is 90 per cent, of that in the male). The cranial part is relatively shorter and wider than in the Gibbon, so the skull is more nearly brachy-cephalic.